模拟降雨下前期含水量对冻融坡面产流产沙过程的影响

发布时间：2018-10-29 15:28

【摘要】：为了探究不同前期含水量条件下冻融作用对坡面降雨侵蚀的影响,采用室内冻融和人工模拟降雨方法研究了不同含水量条件下冻融坡面与未冻融坡面的降雨侵蚀特征。结果表明:黄土坡面的产流时间随前期含水量增大呈先增大后减小的规律,冻融作用使黄土坡面产流时间滞后,其中含水量为20%的坡面经过冻融作用滞后62.50%,最为明显。在产流过程中,20%含水量的冻融坡面比未冻融坡面产流总量低9.14%存在极显著性差异(P0.01)。在产沙过程中,20%和25%含水量的冻融坡面比未冻融坡面产沙总量减小28%,存在极显著性差异(P0.01);20%和25%含水量的冻融坡面与未冻融坡面的可蚀性相差最明显。综上可以得出含水量为20%时冻融作用对坡面产流时间和产流过程影响最显著;含水量为20%和25%时冻融作用对坡面产沙过程和可蚀性K值影响最显著。含水量为20%时产沙量最小,可蚀性最低,可将20%作为黄土最优含水量。
[Abstract]:In order to investigate the effect of freezing and thawing on rainfall erosion of slope surface under different water content, the rainfall erosion characteristics of freeze-thaw slope and non-frozen thawing slope under different water content were studied by indoor freeze-thaw and artificial simulation rainfall methods. The results show that the runoff production time of loess slope surface increases first and then decreases with the increase of water content in the earlier stage. The freeze-thaw effect makes the runoff production time lag behind, and the slope with 20% water content lags behind 62.50 by freezing and thawing action. Most obvious. In the process of runoff production, there was a significant difference (P0.01) between the freezing and thawing slope with 20% water content and the total runoff yield of the frozen and thawed slope without freezing and thawing (P0.01). In the process of sediment production, the total sediment yield of frozen and thawed slope with 20% and 25% water content was 28% lower than that of non-frozen and thawed slope, and there was a significant difference (P0.01). The erodibility of frozen and thawed slope with 20% and 25% water content is the most obvious. It can be concluded that freezing and thawing has the most significant influence on runoff production time and runoff process when water content is 20% and K value is the most significant when water content is 20% and 25% respectively. When the water content is 20, the sediment yield is the smallest and the erodibility is the lowest. 20% can be regarded as the optimum water content of loess.
【作者单位】：西安理工大学西北旱区生态水利工程国家重点实验室培育基地;
【基金】：国家自然科学基金重点项目(41330858);国家自然科学基金面上项目(41471226) 国家重点研发计划项目(2016YFC0402404)
【分类号】：S157.1

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